The present invention generally relates to rolling beds, chairs and twist rolling beds, and more particularly, to a twist rolling bed which provides a human body with physical twist and rolling exercises, and also enables the changing of sleeping posture for health care reasons in a room, hospital, or an office room.
Various beds and chairs that provide for the changing of sleeping or sitting positions statically are known. Beds or chairs, however, which provide the human body with dynamic and continuous rolling or twist rolling, or changing of position either during sleep or at other times, are not available.
For instance, the prior art includes Japanese Pat. Nos. 62-38970, 60-5292, and 60-57327; Utility Model Public Open Nos. 64-28152, 63-38862, 63-128848, 61-45852, 61-107350, and 62-11457; and U.S. Pat. Nos. 4,227,269 and 4,628,556 each of which statically change position or posture before sleep, but not during sleep.
My earlier invention, a rolling bed and chair, described in a Patent application filed on Jul. 9, 1990 in the Patent and Trademark Office of the Republic of Korea, has following disadvantages:
Its first disadvantage is that, because a crank arm is made of a single rod, a shearing force between the crank arm and the connecting rod could be hazardous to a baby who might crawl under the bed. Second, it has no energy saving device. Third, a stop position after rolling was not specified. Fourth, its operational time is not specified. Fifth, its amplitude of vibration is not adjustable. Sixth, its longitudinal inclining device is not attached. Finally, it has no capability for a twist rolling operation.